archy/docker/mempool-frontend/entrypoint.sh

#!/bin/sh
__MEMPOOL_BACKEND_MAINNET_HTTP_HOST__=${BACKEND_MAINNET_HTTP_HOST:=127.0.0.1}
__MEMPOOL_BACKEND_MAINNET_HTTP_PORT__=${BACKEND_MAINNET_HTTP_PORT:=8999}
__MEMPOOL_FRONTEND_HTTP_PORT__=${FRONTEND_HTTP_PORT:=8080}

CONF=/etc/nginx/conf.d/nginx-mempool.conf

# ─── archipelago patch ────────────────────────────────────────────────────
# The stock frontend writes `proxy_pass http://<backend>:8999` with a literal
# hostname and NO resolver, so nginx resolves the backend IP ONCE at worker
# start and caches it for the process lifetime. Podman reassigns the backend
# container's IP whenever it is restarted/recreated (gate, OTA, crash, reboot
# re-IPAM), after which nginx keeps proxying to the dead IP → /api hangs, the
# websocket 502s, and the mempool UI shows "offline" until nginx is reloaded.
#
# Fix: force per-request DNS re-resolution via `resolver` + a variable in
# proxy_pass. Because a variable in proxy_pass disables nginx's automatic
# location→URI rewriting, each block is rewritten to preserve its original
# path mapping exactly:
#   /api/v1/ws, /ws → "/"            (var + "/" replaces the whole URI)
#   /api/v1         → identity       (no-URI proxy_pass passes $uri unchanged)
#   /api/           → /api/v1/$1     (explicit rewrite, then no-URI proxy_pass)
# Operates on the __PLACEHOLDER__ tokens so the host/port sed below fills in
# the concrete values (incl. the `set $mp_backend` line). Idempotent.
# Resolver address: podman's aardvark-dns answers on the network gateway
# (e.g. 10.89.0.1), NOT Docker's 127.0.0.11. Read it from resolv.conf so this
# works on any podman network/subnet (and still falls back for Docker).
ARCHY_RESOLVER=$(awk '/^nameserver/ { print $2; exit }' /etc/resolv.conf 2>/dev/null)
ARCHY_RESOLVER=${ARCHY_RESOLVER:-127.0.0.11}

if ! grep -q 'set \$mp_backend' "$CONF"; then
  awk -v res_addr="$ARCHY_RESOLVER" '
    BEGIN { res = 0 }
    /^[[:space:]]*location / && res == 0 {
      print "\tresolver " res_addr " valid=10s ipv6=off;"
      res = 1
    }
    /proxy_pass http:\/\/__MEMPOOL_BACKEND_MAINNET_HTTP_HOST__:__MEMPOOL_BACKEND_MAINNET_HTTP_PORT__\/;/ {
      print "\t\tset $mp_backend __MEMPOOL_BACKEND_MAINNET_HTTP_HOST__;"
      print "\t\tproxy_pass http://$mp_backend:__MEMPOOL_BACKEND_MAINNET_HTTP_PORT__/;"
      next
    }
    /proxy_pass http:\/\/__MEMPOOL_BACKEND_MAINNET_HTTP_HOST__:__MEMPOOL_BACKEND_MAINNET_HTTP_PORT__\/api\/v1\/;/ {
      print "\t\tset $mp_backend __MEMPOOL_BACKEND_MAINNET_HTTP_HOST__;"
      print "\t\trewrite ^/api/(.*)$ /api/v1/$1 break;"
      print "\t\tproxy_pass http://$mp_backend:__MEMPOOL_BACKEND_MAINNET_HTTP_PORT__;"
      next
    }
    /proxy_pass http:\/\/__MEMPOOL_BACKEND_MAINNET_HTTP_HOST__:__MEMPOOL_BACKEND_MAINNET_HTTP_PORT__\/api\/v1;/ {
      print "\t\tset $mp_backend __MEMPOOL_BACKEND_MAINNET_HTTP_HOST__;"
      print "\t\tproxy_pass http://$mp_backend:__MEMPOOL_BACKEND_MAINNET_HTTP_PORT__;"
      next
    }
    { print }
  ' "$CONF" > "$CONF.archy" && mv "$CONF.archy" "$CONF"
fi
# ─── end archipelago patch ────────────────────────────────────────────────

sed -i "s/__MEMPOOL_BACKEND_MAINNET_HTTP_HOST__/${__MEMPOOL_BACKEND_MAINNET_HTTP_HOST__}/g" /etc/nginx/conf.d/nginx-mempool.conf
sed -i "s/__MEMPOOL_BACKEND_MAINNET_HTTP_PORT__/${__MEMPOOL_BACKEND_MAINNET_HTTP_PORT__}/g" /etc/nginx/conf.d/nginx-mempool.conf

cp /etc/nginx/nginx.conf /patch/nginx.conf
sed -i "s/__MEMPOOL_FRONTEND_HTTP_PORT__/${__MEMPOOL_FRONTEND_HTTP_PORT__}/g" /patch/nginx.conf
cat /patch/nginx.conf > /etc/nginx/nginx.conf

if [ "${LIGHTNING_DETECTED_PORT}" != "" ];then
  export LIGHTNING=true
fi

# Runtime overrides - read env vars defined in docker compose

__MAINNET_ENABLED__=${MAINNET_ENABLED:=true}
__TESTNET_ENABLED__=${TESTNET_ENABLED:=false}
__TESTNET4_ENABLED__=${TESTNET_ENABLED:=false}
__SIGNET_ENABLED__=${SIGNET_ENABLED:=false}
__LIQUID_ENABLED__=${LIQUID_ENABLED:=false}
__LIQUID_TESTNET_ENABLED__=${LIQUID_TESTNET_ENABLED:=false}
__ITEMS_PER_PAGE__=${ITEMS_PER_PAGE:=10}
__KEEP_BLOCKS_AMOUNT__=${KEEP_BLOCKS_AMOUNT:=8}
__NGINX_PROTOCOL__=${NGINX_PROTOCOL:=http}
__NGINX_HOSTNAME__=${NGINX_HOSTNAME:=localhost}
__NGINX_PORT__=${NGINX_PORT:=8999}
__BLOCK_WEIGHT_UNITS__=${BLOCK_WEIGHT_UNITS:=4000000}
__MEMPOOL_BLOCKS_AMOUNT__=${MEMPOOL_BLOCKS_AMOUNT:=8}
__BASE_MODULE__=${BASE_MODULE:=mempool}
__ROOT_NETWORK__=${ROOT_NETWORK:=}
__MEMPOOL_WEBSITE_URL__=${MEMPOOL_WEBSITE_URL:=https://mempool.space}
__LIQUID_WEBSITE_URL__=${LIQUID_WEBSITE_URL:=https://liquid.network}
__MINING_DASHBOARD__=${MINING_DASHBOARD:=true}
__LIGHTNING__=${LIGHTNING:=false}
__AUDIT__=${AUDIT:=false}
__MAINNET_BLOCK_AUDIT_START_HEIGHT__=${MAINNET_BLOCK_AUDIT_START_HEIGHT:=0}
__TESTNET_BLOCK_AUDIT_START_HEIGHT__=${TESTNET_BLOCK_AUDIT_START_HEIGHT:=0}
__SIGNET_BLOCK_AUDIT_START_HEIGHT__=${SIGNET_BLOCK_AUDIT_START_HEIGHT:=0}
__ACCELERATOR__=${ACCELERATOR:=false}
__ACCELERATOR_BUTTON__=${ACCELERATOR_BUTTON:=true}
__SERVICES_API__=${SERVICES_API:=https://mempool.space/api/v1/services}
__PUBLIC_ACCELERATIONS__=${PUBLIC_ACCELERATIONS:=false}
__HISTORICAL_PRICE__=${HISTORICAL_PRICE:=true}
__ADDITIONAL_CURRENCIES__=${ADDITIONAL_CURRENCIES:=false}

# Export as environment variables to be used by envsubst
export __MAINNET_ENABLED__
export __TESTNET_ENABLED__
export __TESTNET4_ENABLED__
export __SIGNET_ENABLED__
export __LIQUID_ENABLED__
export __LIQUID_TESTNET_ENABLED__
export __ITEMS_PER_PAGE__
export __KEEP_BLOCKS_AMOUNT__
export __NGINX_PROTOCOL__
export __NGINX_HOSTNAME__
export __NGINX_PORT__
export __BLOCK_WEIGHT_UNITS__
export __MEMPOOL_BLOCKS_AMOUNT__
export __BASE_MODULE__
export __ROOT_NETWORK__
export __MEMPOOL_WEBSITE_URL__
export __LIQUID_WEBSITE_URL__
export __MINING_DASHBOARD__
export __LIGHTNING__
export __AUDIT__
export __MAINNET_BLOCK_AUDIT_START_HEIGHT__
export __TESTNET_BLOCK_AUDIT_START_HEIGHT__
export __SIGNET_BLOCK_AUDIT_START_HEIGHT__
export __ACCELERATOR__
export __ACCELERATOR_BUTTON__
export __SERVICES_API__
export __PUBLIC_ACCELERATIONS__
export __HISTORICAL_PRICE__
export __ADDITIONAL_CURRENCIES__

folder=$(find /var/www/mempool -name "config.js" | xargs dirname)
echo ${folder}
envsubst < ${folder}/config.template.js > ${folder}/config.js

exec "$@"